Having missing teeth for a long period of time can cause the bone to deteriorate. This may result in having insufficient bone for dental implants. However, we now are able to regrow bone to achieve a suitable foundation for implants.
Major Bone Grafting
Bone grafting can repair implant sites with inadequate bone structure. The bone tissue is either obtained from a tissue bank or your own bone taken from the jaw, hip or tibia (below the knee). Sinus bone grafts can also be performed to restore bone in the posterior upper jaw. In addition, special membranes may be placed in the gum line to encourage bone regeneration.
Major bone grafts are generally performed to repair defects in the jaws. Larger defects are repaired using the patient’s own bone. This bone may be harvested from a variety of sites depending on the size of the defect. The skull, hip, and lateral knee are common sites. These procedures are performed in an operating room and require a hospital stay.
Sinus Lift Procedure
The maxillary sinuses are located behind your cheeks and on top of the upper teeth. Sometimes the roots of the natural upper teeth extend up into the maxillary sinuses, and when these teeth are removed there is often only a thin wall of bone separating the sinuses and the mouth. This often means the bone is insufficient for dental implants.
A sinus graft, or sinus lift graft is when the sinus is entered from where the upper teeth used to be and is then lifted upward and donor bone is inserted into the floor of the sinus. If there is enough bone in the upper jaw ridge and the bottom of the sinus can stabilize the implant well, sinus augmentations and implant placement can sometimes be performed in a single procedure. If there is not sufficient bone, the sinus augmentation will have to be performed before the implantation process and will require several months for the graft to mature.
In more severe cases, the ridge has been reabsorbed and a bone graft is performed to increase ridge height and/or width. This procedure is used to restore the lost bone dimension when the jaw ridge is too thin to support implants. The bony ridge of the jaw is expanded by mechanical means and bone graft material is placed and must mature for a few months before implant placement.
The inferior alveolar nerve, which gives feeling to the lower lip and chin, may need to be moved to make room for the placement of implants in the lower jaw. This procedure may be necessary when the two back molars and/or second premolar are missing. Since this is considered an aggressive procedure (there is almost always some postoperative numbness in the lower lip and jaw area, and it dissipates slowly, if ever), other, less aggressive options are considered first.
The procedure involves an outer section of the cheek of the lower jawbone being removed to expose the nerve and vessel canal. The nerve is then isolated, and the vessel bundle is slightly pulled out to one side. At this time, we will place the implants. The bundle is then released and placed back over the implants. The access area is refilled with bone graft material and the area is then closed.
Typically, an outer section of the cheek side of the lower jawbone is removed in order to expose the nerve and vessel canal. Then we isolate the nerve and vessel bundle in that area and slightly pull it out to the side. At the same time, we will place the implants. Then the bundle is released and placed back over the implants. The surgical access is refilled with bone graft material of the surgeon’s choice and the area is closed.
These procedures may be performed separately or together, depending on the patient’s situation. Bone grafts that are performed using the patient’s own bone generally produce the best results. In many cases, however, we use allograft material for bone grafting, which is prepared from cadavers to promote bone growth on the repair site. The bone tissue is completely safe and very effective. Synthetic materials may also be used to promote bone growth. These surgeries are performed in the out-office surgical site under IV sedation or general anesthesia. Bed rest is recommended for one day with limited physical activity for one week after the procedure.